When you boil a pan of water, it takes a while to heat the water. But the same pan filled with tomato sauce doesn’t take nearly as long. Each substance has a different amount of heat that it takes to change that substance’s temperature. This amount of heat is called the specific heat of that substance. Materials:Two styrofoam cupsOne metal sample of unknown specific heat (tie a string for moving it)One ThermometerVery hot and very cold waterBalance Procedure:Number of your metal sample: _ Mass of your metal sample: _ g 1. Fill one of the cups about half full of cold tap water. Mark the water line on the inside of the cup with a pencil or pen. 2. Pour the water from the first cup into the second cup and again mark the water line on the inside of the cup. This will give you an equal mark in both cups. Empty out the second cup. 3. Fill one of the two cups with HOT water up to the line, and place your metal sample into the cup. Find the mass of the empty second cup. Then fill the second cup with COLD water up to the line, and find the mass of the cold water. mass of empty cup: _ g mass of cup and water:g mass of water (subtract): _ g 4. Place the thermometer into the HOT cup and gently stir the water while watching the temperature. Keep stirring gently until the temperature stops changing. Record the initial temperature of the hot metal (Timetal) here: _ °C. 5. Place the thermometer into the cold water cup and wait for the temperature to stop changing. Record the initial temperature of the cold water (Tiwater) here:_ °C. 6. Remove the metal from the hot water and place it in the cold water. Gently stir the water with the thermometer until the temperature stops changing. Record the final temperature of the water (Tfwater) and metal (Tfmetal) here: _ °C. Wait 5 minutes while watching the temperature and record the highest temperature the thermometer shows. 7. Replace the metal sample and empty the water out of the cups. Return the cups to the lab station.8. Find the heat gained by the cold water. Use the chart to find the specific heat of water.Q = Mass of water x specific heat of water x (Tfwater - Tiwater) Q = _ x _ x ( - _ ) Q = _ Joules 9. Find the specific heat of the metal sample. Remember, if something gains heat (the water) something else must lose heat (the metal sample.) Q for the metal sample will be the same as Q for the water (found in #8). c = - Q ((Tfmetal-Timetal) x mass of metal) c = - ___
(( _ - _) x _ )c = _ J/g°C 10. Ask your instructor for the identity of your metal sample.
Material
Specific Heat
Aluminum
0.903
Brass
0.376
Copper
0.385
Iron
0.450
Lead
0.130
Tin
0.227
Water
4.18
Zinc
0.388
Questions:1. What is the actual c for your metal sample? 2. Find the percent error for your lab? Subtract your answer for procedure #9 from your answer to question #1. Then divide by the answer to question #1. Finally, multiply that answer by 100. 3. How could you change the experiment to get a better calculated c, and how would your change improve the experiment? Think about things that will improve the heat transfer. 4. Which changed the temperature the most, the water or the metal? 5. Why did the metal change a lot and the water only a little?
Time Length
- 1 Day
InstructionsWhen you boil a pan of water, it takes a while to heat the water. But the same pan filled with tomato sauce doesn’t take nearly as long. Each substance has a different amount of heat that it takes to change that substance’s temperature. This amount of heat is called the specific heat of that substance. Materials:Two styrofoam cupsOne metal sample of unknown specific heat (tie a string for moving it)One ThermometerVery hot and very cold waterBalance Procedure:Number of your metal sample: _ Mass of your metal sample: _ g 1. Fill one of the cups about half full of cold tap water. Mark the water line on the inside of the cup with a pencil or pen. 2. Pour the water from the first cup into the second cup and again mark the water line on the inside of the cup. This will give you an equal mark in both cups. Empty out the second cup. 3. Fill one of the two cups with HOT water up to the line, and place your metal sample into the cup. Find the mass of the empty second cup. Then fill the second cup with COLD water up to the line, and find the mass of the cold water. mass of empty cup: _ g mass of cup and water: g mass of water (subtract): _ g 4. Place the thermometer into the HOT cup and gently stir the water while watching the temperature. Keep stirring gently until the temperature stops changing. Record the initial temperature of the hot metal (Timetal) here: _ °C. 5. Place the thermometer into the cold water cup and wait for the temperature to stop changing. Record the initial temperature of the cold water (Tiwater) here:_ °C. 6. Remove the metal from the hot water and place it in the cold water. Gently stir the water with the thermometer until the temperature stops changing. Record the final temperature of the water (Tfwater) and metal (Tfmetal) here: _ °C. Wait 5 minutes while watching the temperature and record the highest temperature the thermometer shows. 7. Replace the metal sample and empty the water out of the cups. Return the cups to the lab station.8. Find the heat gained by the cold water. Use the chart to find the specific heat of water.Q = Mass of water x specific heat of water x (Tfwater - Tiwater) Q = _ x _ x ( - _ ) Q = _ Joules 9. Find the specific heat of the metal sample. Remember, if something gains heat (the water) something else must lose heat (the metal sample.) Q for the metal sample will be the same as Q for the water (found in #8). c = - Q ((Tfmetal-Timetal) x mass of metal) c = - ___